Question

The height of the equilateral triangle is 10cm.Its area is​

Answer 1

Answer:

Let each side be a cm, then

\begin{aligned}

\left(\frac{a}{2}\right)^2+{10}^2 = a^2 \\

<=>\left(a^2-\frac{a^2}{4}\right) = 100 \\

<=> \frac{3a^2}{4} = 100 \\

a^2 = \frac{400}{3} \\

Area = \frac{\sqrt{3}}{4}*a^2 \\

= \left(\frac{\sqrt{3}}{4}*\frac{400}{3}\right)cm^2 \\

= \frac{100}{\sqrt{3}}cm^2

\end{aligned}

Answer 2

Answer:

100/√3cm^2

Explanation:

let each side be a cm

Then,

(a/b)^2+(10)^2=a^2

[a^2-(a^2/4)]=100

3a^2/4=100

a^2=400/3

Area=(√3/4)a^2

=[(√3/4)(100/3)]cm^2

=110/√3cm^2